Fuel systems used in state-of-the-art internal combustion engines are relatively complex and sophisticated electromechanical systems. The associated engines can be direct-injected where fuel injectors extend into the engine cylinders, port-injected where fuel is delivered into a port in communication with an engine cylinder, or structured according to yet another strategy. In the case of compression ignition diesel engines it is typical for liquid fuel injection pressures to be as high as several hundred megapascals (MPa). Injections can occur multiple times per second, necessitating rapid travel of moving parts within the fuel injector in response to electromagnetic actuation forces and/or rapid pressure changes, and resulting in relatively intense, repetitive impacts, and in some instances a tendency toward liquid cavitation. The timing and manner of injection of fuel is typically relatively tightly controlled, with opening and closing of valves desirably quite rapid to produce so-called “square” injection rate shapes, ramp shapes, and still others.
Pressurization of the fuel to be injected can take place within the fuel injector itself, such as by way of a hydraulically actuated or cam-actuated plunger, or externally such that pressurized fuel is stored in a common rail or the like and a reservoir of pressurized fuel maintained for multiple fuel injectors. Due to the foregoing and other factors, fuel injectors are often purpose-built for certain fuel injection strategies and combustion recipes. One example fuel injector for an internal combustion engine is known from U.S. Pat. No. 7,556,017 to Gibson et al.